Plastic pipe and plastic fittings are used in many sewer and water pipe installations, both for the main water and sewer lines as well as for connecting individual residences or commercial buildings to the main lines. Such plastic pipe and plastic pipe fittings have, in the past, been bonded together to form a single, rigid pipe network. Such a network, however, is incapable of flexing sufficiently to reliably accomodate the stresses arising from burying the pipe in its trench or from shifting of the earth. Repairs to such networks are also difficult since the pipe must be cut apart to remove a defective section or install a fitting. Accordingly, many water and sewer pipe installations which are made with plastic pipe are joined using an annular elastomeric seal. This seal is normally mounted in the enlarged end of the pipe or fitting. The beveled end of a pipe is then forced into the seal in the enlarged end of the pipe or fitting. The fit is sufficiently tight to seal the two pipes or the pipe and fitting to one another without the use of glues, caulking compounds or fastening devices.
Typically, plastic pipe is made by the manufacturers in standard lengths with one end being beveled to facilitate the insertion of the pipe into the seal. The other end of the pipe is enlarged to the proper diameter to receive a seal and the beveled end of a pipe.
When pipes of other than standard length are required, a pipe of standard length has heretofor generally been cut off in the field using an abrasive disc cutting device. Such a device is similar in configuration to a chain saw with the exception that a support arm is mounted in place of the saw bar. A shaft is rotatably mounted at the end of the support bar and extends transversely through the arm. The shaft is rotatably driven by a belt and pulley drive mechanism and an abrasive disc is mounted on the end of the shaft opposite the pulley. The abrasive disk is rotated at a high rate of speed by the motor of the cutting device.
The cutting of the pipe is accomplished by bringing the rotating abrasive disc into contact with the pipe as it lies on the ground. Typically, the operator rolls the pipe along the ground as necessary with his foot until the cut is completed. Since no guide is provided for cutting of the pipe, the cut end of the pipe frequently is irregular and may not be perpendicular to the longitudinal axis of the pipe.
Once the pipe has been cut according to this method it is necessary to put a bevel on the cut end in order to facilitate insertion of the pipe into a seal mounted in the enlarged end of a pipe or fitting. This is generally accomplished by bringing the side of the rotating abrasive disc against the pipe at the appropriate angle and grinding the bevel onto the pipe. The pipe is again rotated as necessary so that it can be beveled about its entire circumference. It is difficult to control the cutting device in such circumstances, however, and the bevel is thus frequently very irregular. In addition, this grinding procedure frequently results in the bevel extending between the inner and outer surfaces of the pipe wall. In such case, the angle of incline of the bevel is quite steep making it difficult to force the seal onto the pipe end.
This task of cutting and beveling the pipe is not only difficult and time consuming but also produces a great deal of dust which is harmful both to the engine of the cut off device and to the person operating such device. In addition, a certain danger is involved in operating such a cut off device since the rapidly rotating disc may break and eject fragments of the abrasive material at relatively high speeds. The abrasive disc may also be brought into contact with rocks or other debris during the cutting and beveling operation resulting in such debris being thrown at relatively high speeds.
This method of cutting pipe also results in waste since small sections of the pipe formed when a pipe is cut to length are frequently discarded because of the difficulty of beveling them.